1. Field of the Invention
The present invention relates to a lens barrel enabling a high power zoom operation and a method of operation of a lens barrel.
2. Description of the Related Art
As a prior art, a lens barrel employing an inner focus system and enabling a high power zoom operation is known. As prior art, for example Japanese Patent Publication (A) No. 7-333482 is known.
Conventional lens barrels, in particular lens barrels called “high powered” with zoom powers of over 10× as required for recent lens barrels, have the problems of too large movement of the lenses and the inability to be similarly configured.
Further, if giving priority to the design of the shapes of the focus cam grooves for correcting the amount of feed of the focusing lens accompanying a change in focal distance, the inclined faces of the cam grooves operating at the time of a zoom-operation will end up becoming too sharp and therefore a zoom drive operation utilizing cam grooves will no longer be able to be achieved.